My [Juan Cole's] own theory is that Morsi has been moving toward the center, at least symbolically, since his election. He is talking about appointing a Coptic Christian and a woman vice president. In moving to the center, he risks losing the support of the fundamentalist hardliners. (Many Egyptians are convinced that he will do a backroom deal with the military council).
Calling for Abdel Rahman's release is a cheap way to signal to the other fundamentalists that he is still one of them. The US is not in fact going to release the blind Sheikh, so he faces no real-world problem of dealing with such a release. It is just hot air.
Likewise, the call serves to put Washington on notice that he is no Hosni Mubarak, and the days of the US and Israel hearing sweet nothings from the president of Egypt are over. He went on to underline that Egypt is an independent country and will have an independent foreign policy.
Interesting points on Morsi. Juan is wrong about this though: "Morsi is a fundamentalist, and make no mistake, he wants to impose a rigid medieval conception of Islamic law on Egypt." The Brotherhood really has changed. The youths are changing it too. It's just the way it is. Sure, there will be foot dragging and backsliding, but I don't see Egypt becoming even as Iran. I just don't see it.